On Mon, Mar 23, 2015 at 07:42:02PM -0700, Constantine A. Murenin wrote: > On 23 March 2015 at 15:59, Stuart Henderson <st...@openbsd.org> wrote: > > On 2015/03/23 10:14, Constantine A. Murenin wrote: > >> May I also ask why is it necessary to remove the timestamp information > >> from the tar archives themselves? > > > > To improve rsyncability. > > Could you elaborate? > > 0. Doesn't rsync ignore timestamps by default anyways? > > 1. Doesn't src/usr.sbin/pkg_add/OpenBSD/ArcCheck.pm#rev1.29 wipe out > the timestamps only directly from the tar archives, still leaving them > intact otherwise? > > C.
Dude. Not having timestamps means that when files don't change, the archive chunk doesn't change. We do gzip them by chunks as well, so when a big package like texlive gets updated, a lot of time, most of the actual .tgz package file *doesn't change at all*. Put back timestamps in the tarball, and gzip will compress things differently, thus destroying rsyncability completely.
